D.C. United put itself in a good position to advance to the semifinals of the SuperLiga with a 1-0 win against Mexican power Club America before 18,604 at RFK Stadium last night.

United peppered the opposition all evening, finally giving its nervous fans a win on the back of Rod Dyachenko’s early strike. It was a nail-biting victory, though, considering United’s recent habit of blowing leads.

“We scored that goal in the 12th minute and took the wind out of them,” United coach Tom Soehn said. “I was hoping we would get that second one, but that first goal meant so much.”

United outshot the Mexican-based club 16-2, and United goalie Troy Perkins didn’t have to make a save. Still, United made what should have been an easy win look hard by failing to convert more of its chances.

“As long as we keep the ball out of our net I’m not going to worry about that,” United midfielder Brian Carroll said. “As long as we come away with the win I’m happy.”

The victory helped United break a five-game winless streak in all competitions.

After a disappointing 1-1 tie with Mexican club Monarcas Morelia last week in its SuperLiga opener, United now has four points going into its final game in group B against the Houston Dynamo on Wednesday and possibly needs just a tie to advance.

Against Morelia, United failed to capitalize on a 30-minute, one-man advantage and allowed the tying goal. Last night, Club America had a man sent off just shortly after the break, but United made sure there were no slip-ups.

“It’s an important game to get the result at home because we lost the last one,” Soehn said. “The situation was very similar and I thought if you use every experience you can make yourself better. I thought the guys responded very well and we adjusted our formation better and the energy level was high. We closed them off and we did a good job with the ball.”

Soehn went with the same lineup as the Morelia game, with Dyachenko, in for the injured Jaime Moreno, alongside Luciano Emilio on the attack.

That lineup paid off, and Dyachenko worked hard to get himself in a good position in the fifth minute, delivering a fine shot against goalie Armando Navarrete. But the breakthrough for United came in the 12th minute, when Dyachenko’s instincts paid off.

Ben Olsen floated over a cross from the right flank and Christian Gomez, hovering on the corner of the six-yard box, headed the ball into the path of Dyachenko, who from 13 yards out, hammered a low left-footed shot past Navarrete to stun the yellow-clad pro-Club America crowd.

“I saw Christian make a far post run and I knew he would knock it back across the box, so I did my best to get inside the box and was fortunate to get good contact on the ball,” Dyachenko said.

Gomez was causing all kinds of trouble, and he had his own splendid shot hit off the bar.

After blowing a number of leads recently, United seemed eager to put away the game away early. Bobby Boswell nearly made it 2-0 minutes before the break, but his effort was smothered by the goalie.

United came out in the second half looking for an insurance goal. It got some help when Club America went down to 10 men in the 49th minute after Oscar Rojas was red-carded for his wild two-footed tackle on Marc Burch.

Soehn sent on midfielder Clyde Simms for Dyachenko in the 58th minute. Emilio, as the lone forward, blew a perfect chance to increase the lead when his header sailed wide with only the goalie to beat.

Soehn fortified his defense late in the match by sending on defender Bryan Namoff for the hard-working Gomez.

“Tonight I think we were more organized defensively,” Perkins said. “We withstood them for the first 15 minutes and everything they threw at us. We knew they were going to press us and then we opened the game up and stuck with our game plan and kept the ball.”

Club America, which looked very much still in preseason form, is one of Mexico’s most storied teams after winning 10 Mexican league titles and five CONCACAF Champions’ Cups.

The SuperLiga pits the top four American teams against Mexico’s top four clubs. The top two teams from each group advance to the semifinals with the winner taking home $1 million.